Timepiece having a nuclear power source

ABSTRACT

A timepiece comprising a nuclear power source in a capsule having a sensitive insulation of an output terminal, this insulation and output terminal respectively being protected by a protecting plate forming an intermediate back.

United States Patent [191 Adler et al.

[ Feb. 12, 1974 TIMEPIECE HAVING A NUCLEAR POWER SOURCE [75] Inventors:Karl Adler, Grenchen; Georges Ducommun, Feldbrunnen, both of Switzerland[73] Assignee: Biviator S. A., Grenchen,

Switzerland [22] Filed: Feb. 8, 1971 [21] Appl. No.: 112,920

[30] Foreign Application Priority Data Feb. 23, 1970 Switzerland 2551/70[52] US. Cl. 58/23 BA, 58/53, 58/90 [51] Int. CL... G04c 3/00, G04b37/00, G04b 37/08 [58] Field of Search 29/77-79; 58/23 R,

58/23 BA, 23 C, 50 R, 23, 90; 224/4 R Primary ExaminerRichard B.Wilkinson Assistant Examiner-Edith Simmons Jackmon Attorney, Agent, orFirmDwight H. Smiley; Imirie & Smiley ABSTRACT A timepiece comprising anuclear power source in a capsule having a sensitive insulation of anoutput terminal, this insulation and output terminal respectively beingprotected by a protecting plate forming an intermediate back.

5 Claims, 2 Drawing Figures //L I; Y F k I 1 I 1L J c 1 3 5 A r 4 s 2123 TIMEPIECE HAVING A NUCLEAR POWER SOURCE BACKGROUND OF THE INVENTIONElectric or electronically powered timepieces, such as watches, comprisea separate battery that is removably positioned within the watch case toenable replacement thereof when the battery power finally is dissipated.In the usual electric battery-operated watch the battery life isapproximately one year, more or less, and must be replaced by an expert.During the normal life of a watch of this type the battery will have tobe replaced a number of times and, on such occasions, the timepiece mustbe taken to a watch expert to effect such replacement. Regardless of thenature of the battery the case for the timepiece must be somewhat largerthan desirable because the battery is a separate item.

It has been discovered that a radioactive or nuclear isotopic powersource may be provided as a battery for providing the power for drivingan electric watch, as disclosed in U.S. Pat. No. 3,562,613, but thenuclear power source must be included within a vacuum sealed case havinga closure to enable the evacuation of the interior and a protectingplate protecting such closure from damage and the loss of vacuum withattendant possible excape of radiation and this enclosing structure isspace consuming and, although such power source will normally last thelife of the timepiece, as a separate battery it does not reduce thespace requirements.

SUMMARY OF THE INVENTION According to the present invention, a nuclearisopic power source may be enclosed within a calotte surrounded by awall and constituting a part of the casing for the timepiece. The powersource is located within the calotte which is enclosed by a cover withinthe easing and sealed to the calotte wall, which cover has an apertureto enable evacuation of the chamber formed by the calotte and cover,which thereafter is sealed by a closure. A protecting plate is fixed tothe calotte wall in spaced relation to the cover to mechanically protectthe cover and closure. A drive shaft for the timepiece movementmechanism within the casing may extend through an opening in theprotecting plate without danger of the excape of radiation.

BRIEF DESCRIPTION OF THE DRAWING FIGS. 1 and 2 are diametrical sectionalviews of two embodiments, respectively.

DETAILED DESCRIPTION OF THE INVENTION The watch of the first embodiment(FIG. 1) includes a case of which is shown a caseband l, in which isscrewed a tubular piece 11 constituting a part of the back of thewatch-case. This tubular piece 11 has an external flange 23 whichcompresses a Water resistant gasket 3. The glass of the watch-case andthe movement of the watch are not represented.

The watch includes a nuclear isotopic power source of the typedescribed, e.g. in US. Pat. No. 3,562,613. Such a power sourceconstitutes a system for direct conversion of radioactive radiationpower into electric power. The power source consists of a waterresistant screened caspule which prevents any dangerous radioactiveradiation to the outside.

The isotopic power source comprises an envelope formed by a calotte 4and a cover 5, the latter being pressed or soldered in a water resistantmanner on the calotte 4. In the cavity of the calotte 4 are fitted theactive elements of the power source which are denoted by the referencenumeral 6 and are not described in detail. Numeral 7 designates a glassor crystal bulb which permits making a vacuum inside of the source andwhich afterwards is hermetically sealed. The join between this bulb 7and the cover 5 is also perfectly water resistant. A protection plate 8,disposed above the bulb 7 is fixed by any suitable means on a shoulderof the wall of the calotte 4. This protection plate 8 presents a hole 9allowing e.g. to introduce a shaft of a gear of the watch. It protectsalso the bulb 7 mechanically and constitutes an intermediate back. Aconductor 21 connects the active elements 6 of the power source with apiece of the watch movement; it is embedded in the bulb 7, goes out ofthe latter and passes through an isolated socket 22, driven into theprotection plate 8. The bulb 7 with its conductor 21 constitutes anisolated outlet of the capsule containing the isotopic power source.

In a modified embodiment, the bulb 7 might be made from plasticmaterial, but in any case it is very delicate piece which does notsupport any shock or high pressure. That is why it must be protected bythe plate 8.

The calotte 4, constituting a part of the envelope of the power source,is fitted in the tubular piece 11 and constitutes a part of the back ofthe watch-case. The other part of the back of the watch-case is formed,as already said,by the tubulair piece 11 itself.

In the second embodiment (FIG. 2), the power source includes an envelopeformed by a calotte l2 and a water resistant cover 13. The calotte 12forms itself the back of the watch-case, on which the case-band 14 issnap-fitted. A protection plate 15, constituting an intermediate backand presenting a hole 16 is disposed above the bulb 7 and is fixed on ashoulder of the back 12. A pillar-plate 17 of the watch movement,presenting a hole 18 for the passage of the bulb 7, is fixed on ashoulder of the back 12 and carries pillars 19 which in turn support abridge 20. The pillars 19 go through holes in the protection plate 15and are anchored in the back 12.

What we claim is:

l. A timepiece comprising a casing for housing a timepiece mechanism, anevacuated capsule containing a nuclear isotopic power source enclosed insaid casing and having a mechanically sensitive seal for the vacuum inthe capsule, and a protection plate in said casing for protecting saidseal from mechanical displacement, said plate constituting anintermediate back of said casing and separating said capsule from thetimepiece mechanism.

2. A timepiece comprising a casing including a calotte surrounded by awall, a cover within said casing and sealed to said calotte to define achamber therebetween, said cover having an aperture to enable evacuationof said chamber, a closure sealing said aperture to maintain a vacuum insaid chamber, a nuclear isotopic power source within said vacuumchamber, and a protecting plate fixed to said calotte wall in spacedrelation to said cover and mechanically protecting said source andclosure.

3. A timepiece according to claim 2, wherein the seal between saidcalotte and cover is water resistant.

4. A timepiece according to claim 3 said calotte constitutes a part ofthe back of the case of the timepiece.

5. A timepiece according to claim 3 wherein said calotte forms the backof the case of the timepiece.

UNITED STATES PATENT .OFEIICE CERTIFICATE OF CORRECTION Patent No. 3,79113h Dated February 12, 197

Inventor) Karl Adler & Georges Ducommun It is certified that errorappears in the aboveidentified patent hat said Letters Patent are herebycorrected as and t shown below:

In the Claims 2 M claim line 13 after "claim 3,", insert wherein Signedand sealed this 6th day of August 197 (SEAL) Attest: v

MCCOY M. GIBSON, JR. 0. MARSHALL DANNY Attesting Officer Commissioner ofPatents ll PO-IOSO (IO-69) USCOMM-DC 6D376-P69 U.S. GOVERNMENT PRINTINGOFFICE 1 l9! 0-366-334 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3,791,13h Dated February 12, 197

Inventor) Karl Adler & Georges Ducommun It is Certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

In the Claims: M

Claim H a line 3 after "claim 3,", insert I wherein Signed and sealedthis 6th day of August 197A.

(SEAL) Attest: v

MCCOY M. GIBSON, JR. 0. MARSHALL DANN Attes'ting Officer Commissioner ofPatents USCOMM-DC 60376-5 69 u.s. GOVERNMENT PRINTING OFFICE I969o-ass-su :M PO-IOSO (IO-69)

1. A timepiece comprising a casing for housing a timepiece mechanism, an evacuated capsule containing a nuclear isotopic power source enclosed in said casing and having a mechanically sensitive seal for the vacuum in the capsule, and a protection plate in said casing for protecting said seal from mechanical displacement, said plate constituting an intermediate back of said casing and separating said capsule from the timepiece mechanism.
 2. A timepiece comprising a casing including a calotte surrounded by a wall, a cover within said casing and sealed to said calotte to define a chamber therebetween, said cover having an aperture to enable evacuation of said chamber, a closure sealing said aperture to maintain a vacuum in said chamber, a nuclear isotopic power source within said vacuum chamber, and a protecting plate fixed to said calotte wall in spaced relation to said cover and mechanically protecting said source and closure.
 3. A timepiece according to claim 2, wherein the seal between said calotte and cover is water resistant.
 4. A timepiece according to claim 3 said calotte constitutes a part of the back of the case of the timepiece.
 5. A timepiece according to claim 3 wherein said calotte forms the back of the case of the timepiece. 